The technical field of this invention relates to matrices for cellular attachment and growth. The invention also relates to methods of making and using these matrices for tissue engineering and the construction of artificial blood vessels.
Diseases of small and medium caliber arteries account for the majority of deaths in the United States each year. Over 500,000 coronary bypass grafts and 50,000 peripheral bypass grafts are performed annually in Europe and in the United States. However, up to 30% of the patients who require arterial bypass surgery lack suitable or sufficient amounts of suitable autologous conduits such as small caliber arteries or saphenous veins, which remain the standard conduit for coronary bypass surgery.
Synthetic grafts, such as polytetrafluoroethylene (PTFE) or Dacron (polyethylene terephthalate fiber) have been used to bypass large caliber high-flow blood vessels. However, these grafts fail when used to bypass small-caliber, low flow blood vessels due to increased thrombogenicity and accelerated intimal thickening leading to early graft stenosis and occlusion.
In the last two decades many attempts have been made to engineer patent small-caliber (<5-6 mm) arterial substitutes. However, these substitutes exhibited poor mechanical and burst strengths which precluded in vivo implantation.
Accordingly, a need exists for creating improved matrices for tissue engineering of blood vessels. In particular, a need exists for creating matrices that have a similar composition and ultrastructure to native scaffold materials that can locally deliver a therapeutic agent that aids in developing the artificial tissue construct.